Literature data indicated that [68Ga]Ga-NOTA-MAL-Cys39-exendin-4 detection rate may decrease in case of small lesions, in case of malignant insulinomas (in which SSTRs are expressed with high density, whereas GLP-1 receptor expression is decreased or absent) and for lesions in the distal pancreas tail, next to the left kidney (site of physiological radiotracer excretion) [41••]. Here, GLP1R is linked to pancreatic insulinoma.